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MontanaS
09-30-2008, 12:13 AM
I'm new to shooting cast and have run into a situation where I could use some input. I'm shooting a 40-65 rolling block with a 400 grain Snover bullet. This bullet and caliber had listed with it load data for eleven different powders. One was with Varget which is a powder I dearly love in my Kar 98. Since I had it on hand I decided to work up some loads. I began with the minimum load which was 28.5 grains. Every round had sever blow back with residue all over the cases. The cases also stuck in the chamber. I suspected that this was because not enough pressure. The CUP for that amount listed 8,200. So I worked up ten more loads but with 30.5 grains. Blow back still occured but was significantly less, coating only .5" of the neck. The cases still stuck in the chamber but were more easily removed. Didn't have to bang on the ejecter as before but just push down a little harder. I received a very tight group at 100 yds with this load. Am I correct in assuming that if I up the grains to say 31.5 (33.5 is maximum) the blowback and sticking in the chamber problem should dissappear? I should also note that no leading has yet occurred but with the higher pressure it might.

Dale53
09-30-2008, 12:37 AM
I have shot a LOT of 40/65 with duplex loads (10%, by weight of RL-7 and the rest black powder). This load will give you around 1350 fps, burns very clean,and you can shoot it all day without blow tubing or wiping.

I have also used a 40/65 in NRA Silhouette shooting where only black powder is allowed. My preference there is Swiss 1½ compressed about .075" (determined by accuracy in the specific rifle).

If you need/want to use smokeless, RL-7 is a good powder for most of the old black powder rounds in appropriate charges.

Dale53

Doc Highwall
09-30-2008, 08:09 PM
I would suspect that your cases are to hard and need to be annealed. When the cases are hard they do not allow the case to seal the chamber allowing blow back. Brand new cases such as Starline have been known for having to be annealed when brand new.

Bad Ass Wallace
09-30-2008, 08:57 PM
I had a similar problem with my Sharps. The problem was traced to the cases. Winchester cases were .0503 dia just in front of the rim while Remington mike at 0.498. A switch to Rem and case forming was much easier and blowback almost nil.

A batch of 40/65 Starline have also proven to be good and measure the same as the Remington 45/70 ones.

MontanaS
09-30-2008, 10:27 PM
Thanks for the input. But I guess I could elaborate more. There were 100 cases in this batch. Fifty of them had already been loaded with the same bullet but with 20grains of 5744. Not a single one of them had any blow back nor did any of them stick in the chamber. The fifty I loaded with Varget I taper crimped with the same die that the man who loaded and gave me the loaded cases used. He was with me when the ones I loaded were showing blowback and getting stuck. He was as miffed as I was but also guessed that it might be the low load. I am going to try again tomorrow with 31.5 grains Varget and see. Will report results.

GARD72977
09-30-2008, 11:47 PM
I think the problem might be more when the loads are creating pressure rather than how much pressure they are creating. The dia right in front of the rim will stop blow back but not a sticky ejection caused by powder residue. The varget load may not preduce pressure as fast as the 5744 Load. This would explain why one load had blow back and another load with the same pressure did not. It sounds like the Varget is just letting gasses by the brass before it greates enough pressure to seal the brass to the chamber. I would not increase the load above the max. I agree with Doc Highwall annealing your cases should solve your problem.